Renal

Question 1

Tx of Nephrotic Syndrome in Kids

Answer 1

STEROIDS (90% are responsive); if not responsive then get kidney biopsy

• Prednisone 2 mg/kg/day for 6 weeks; then 1.5 mg/kg/day for another 6 weeks
• If relapse … 2 mg/kg/day until neg protein in urine for 3 full days; then taper over 1 mo
• If frequent relapse … 2 mg/kg/day until neg protein in urine for 3 full days; then taper over 2-3 mo
• May have to try immune-suppressive agents if not responsive to steroids (tacrolimus, cyclosporine, mycophenoalte)

Question 2

Nephritic Syndrome Labs

Answer 2

• UA - hematuria, RBC cats, protein
• Urine electrolytes and FENa
• CBC, CMP, ESR
• Viral serologies
• Complement levels
• ANA, ASO titers, ANCA, IgA, GBM antibodies

Question 3

What etiologies of nephritic syndrome are associated w/ low complement levels?

Answer 3

• Low C3 - MPGN, PIGN

* Low C3 and C4 - SLE nephritis

Question 4

Risk Factors for Kidney Stones in Kids

Answer 4

• Anything that causes urinary stasis - structural abnormalities
• Distal renal tubular acidosis
• ADPKD
• Loops - inc Ca in urine
• Diet high in calcium or ketogenic
• Cystinosis
• CF or IBD - fat malabsorption so fat binds Ca leaving oxalate free
• Wilson Disease
• Infection –> urease –> alkalotic urine pH
  Lesch-Nyhan = urate stones (orange in diaper)

Question 5

Causes of Hemorrhagic Cystitis

Answer 5

• Adenovirus
• Meds - cyclophosphamide, PCN, dyes, insecticides
• Radiation
• Trauma

Question 6

VUR Pathophysiology

Answer 6

• Retrograde flow from bladder to upper urinary tract
• From inadequate closure at junction during bladder contraction (shorter ureter segment where it inserts at bladder wall)

OR abnormally high bladder pressure prevents closing (may be due to neurogenic or anatomic reasons)

• Infected urine –> kidney –> scarring and poor growth –> CKD if bilateral (so promptly treat all UTIs)

Question 7

VUR Grading

Answer 7

BASED ON VCUG

• I - reflux into ureter w/o dilation
• II - reflux into ureter and collecting system w/o dilation
• III - reflux into ureter and collecting system w/ mild dilation
• IV - reflux in both w/ more significant dilation and blunting of calyces
• V - massive reflux, tortuous ureter and dilation everywhere

Question 8

Posterior Urethral Valves

Answer 8

• Membranous folds on posterior urethra in males –> bladder hypertrophy, hydrometer, hydronephrosis
• Presentation
  
  • Obstructive sx, abdominal distention
  • UTI, little boy w/ poor stream
• Dx
  
  • Prenatal US
  • Later US showing hydropnephrosis
  • VCUG
• Tx - correct electrolytes, immediate catheterization,
  cystoscopic ablation of valves

Question 9

Auto Dom v. Auto Rec Polycystic Kidney Disease

Answer 9

DOMINANT

* Cysts on all parts of nephron 
* Also cysts of liver, pancreas, cardiovascular system 
* Usually present in adulthood
* Mgt - watch and support, may need anti-hypertensives later in life 

RECESSIVE

* Dilation of collecting ducts and hepatic fibrosis 
* Seen at birth or on prenatal US 
* HTN, oligouria, palpable abdominal mass, poor feeding, enlarged liver, growth failure 
* Labs - UA, CBC, LFTs, liver and renal US 
* Tx - dialysis, transplant, anti-hypertensives

Question 10

2 Types of Priapism

Answer 10

ISCHEMIC

* EMERGENCY 
* Tissue damage after 4-6 hrs
* Prolonged erection --> compartment syndrome 
* Doppler shows little or no flow
* Associated w/ sickle cell 
* Immediate urological intervention and pain meds 

NON-ISCHEMIC

* Not urgent (b/c cavernous blood is well-oxygenated) 
* Fistula /n cavernosal artery and corpus cavernosum often associated w/ blunt trauma or needle injury 
* Less rigid and painful 
* Conservative management; usually resolves in days